Palletising device

ABSTRACT

A palletizing device ( 10 ) comprising a lower plane ( 15 ) able to supportingly receive a pallet ( 5 ) and a loading device ( 100 ) vertically mobile above the lower plane ( 15 ) and comprising an upper platform ( 110 ), superposed in plan view on the lower plane ( 15 ) and provided with variable-configuration support means ( 112 ) and activating means able to cyclically move the support means ( 112 ) between a closed configuration, in which the define a support for a first layer of products ( 4 ) to be palletized, and an open configuration, in which they remove the support in order to release the first layer of products ( 4 ) downwards, in which the loading device ( 100 ) comprises a storing platform ( 120 ) defining a support for a second layer of products ( 4 ) to be palletized and flanked to the upper platform ( 110 ).

TECHNICAL FIELD

The present invention relates to a palletizing device, i.e. an automaticdevice for stacking packed products on pallets, such as for examplepacks of bottles. In more detail, the present invention relates to apalletizing device of a type comprising a fixed platform able to supportthe pallet arranged along the transfer line thereof, a supply line ofthe products arranged at a fixed height, a mobile upper platformvertically aligned with the fixed platform.

PRIOR ART

As is known, in a palletizing device of the above type, the upperplatform comprises variable-configuration support means, typically aslatted platform, which support means are moved by relative activatingmeans between a closed configuration, in which they exhibit a load planeable to restingly support the products to be palletized, and an openconfiguration, in which they remove the support, letting the productsfall downwards by force of gravity.

The palletizing device is located on a more complex palletizing plantwhich comprises, connected to the upper platform, a further followingplatform which is also vertically mobile and is such as to:

collect a layer of products to be palletized by the conveyor line andgroup them, placing itself at the level of the line,move vertically such as to place itself at the level at which the upperplatform is located in the given instant andtransfer the layer of products to be palletized on the support means ofthe upper platform.

In practice, when the support means are in the closed configuration, theproducts to be palletized are raised horizontally on the loading plane,in such a way as to form thereon a layer of grouped products, afterwhich the support means are brought into the open configuration, suchthat the layer of products rests directly on the pallet that is borne bythe underlying lower platform.

At this point, the upper platform is raised by a quantity that issubstantially equal to the height of the products collected on thepallet, and the support means of the upper platform are brought into theclosed configuration, in order thus to be able to receive a furtherlayer of products.

This cycle is repeated several times up to the formation on the palletof a complete stack of products.

At the end of operations, the lower platform is activated such that thecompletely loaded pallet can be distanced from the conveyor line towardsfurther operating stations, and be replaced by another and empty pallet.

Further, the palletizing plant generally comprises means for positioninga cardboard sheet between a layer of products and another, aimed atgiving the stack of palletized products a greater stability.

In particular, use is known of a collecting and positioning turret of asingle cardboard sheet located by a side of the palletizing device,which comprises a mobile arm able to collect the cardboard sheet from astack of sheets and position it on the layer of products once the layeris made available on the upper platform.

If on the one hand these palletizing plants have shown a particulareffectiveness in the carrying-out of the stacking operations of theproducts and the palletization thereof, a drawback encountered is thatthey exhibit a relatively low efficiency due to the existence ofnumerous dead times necessary for ensuring transfer and positioning ofthe layer of products to be palletized, as well as the cardboard sheet,among the various components that constitute the plant and which arededicated to the palletizing device.

In particular, once the upper platform has unloaded the layer ofproducts on the pallet it is necessary to wait for the follower platformto take delivery from the conveyor and grouping line of the products tobe palletized of a new layer and returns to the level reached by theupper platform in order to transfer the new layer of products thereon.

Further, once the new layer of products is received by the upperplatform, before it is stacked on the pallet it is necessary to wait forthe necessary time so that the collecting and positioning turret of thecardboard sheet positions the sheet restingly on the new layer ofproducts.

An example of a palletizing device, according to the preamble of claim1, is disclosed in the U.S. Pat. No. 4,205,934.

An aim of the present invention is to obviate the mentioned drawbacks ofthe prior art, thus increasing the efficiency of the whole palletizingplant, with a solution that is simple, rational and relativelyinexpensive.

The aims are attained by the characteristics of the invention reportedin the independent claim. The dependent claims delineate preferredand/or particularly advantageous aspects of the invention.

DISCLOSURE OF THE INVENTION

in particular, the invention discloses a palletizing device comprising alower plane able to supportingly receive a pallet and a loading devicethat is vertically mobile above the lower plane and comprising an upperplatform, superposed in plan view on the lower plane and provided withsupport means having a variable configuration and activating means ableto cyclically move the support means between a closed configuration, inwhich they define a support for a first layer of products to bepalletized, and an open configuration, in which they remove the supportin order to release the first layer of products downwards.

According to the invention, the loading device comprises a storageplatform defining a support for a second layer of products to bepalletized which is flanked to and solidly constrained to the upperplatform.

Thanks to this solution, the waiting time required for depositing afollowing layer of products on the pallet can be significantly reduced,making the whole palletizing plant more efficient.

In a further aspect of the invention the loading device comprises apositioning organ, overlying the upper platform and located on-board theloading device, able to position and release a sheet support element onthe first layer of products.

Thanks to this it is possible to further reduce the predisposing anddepositing times of a layer of products on pallets, considerablyimproving both the stability of the stack and the efficiency of thewhole palletizing plant.

A still further aspect of the invention is that the loading devicecomprises a storage plane of at least a stack of sheet elementscommanded by the positioning organ.

In this way, a quantity of sheet elements is made available on theloading device, such as to be able to carry out a depositing of adeterminable number of layers of products without any interruption ofthe palletizing plant and with a considerable saving in terms of time,while at the same time reducing the overall volumes of the palletizingplant.

The loading device advantageously comprises conveyor means of a sheetelement at a time which means are provided with a gripping system of asheet element of the stack of sheet elements and a translation system ofthe gripped sheet element, able to bring the gripped sheet element intoan unloading position, in which the sheet is substantially superposed inplan view on the first layer of products.

In this way the positioning of the sheet element on the first layer ofproducts to be stacked on the pallet and especially fast, effective andprecise.

The gripping system advantageously comprises at least a first suckerthat can be arranged in a loading position, in which it is superposedabove the stack of sheet elements, for gripping the uppermost sheetelement from above, the translation system being able to translate thefirst sucker alternatively between the loading position and theunloading position.

Thanks to this solution, the gripping of the sheet element to bepositioned on the first layer of products is particularly effective andin no way ruins the sheet element.

Further, the first sucker comprises a deformable cup in which a conduitopens that is associated to an aspirating group able to define a slightdepression at the internal zone of the deformable cup.

In this way the grip of the sheet element is particularly stable andenables effective transport of the sheet element from the loadingposition to the unloading position.

In a further aspect of the invention the positioning organ comprises atleast an arm, for example provided with at least a second sucker, andvertically mobile between a raised position, in which it is at a higherlevel than the first sucker in the unloading position, and a loweredposition, in which it is resting on the first layer of products with thesheet element interposed.

With this solution, the positioning organ accompanies the positioning ofthe sheet element on the first layer of products, maintaining itperfectly centred and stably fixed thereto, from the moment ofdetachment thereof from the first suckers up to the release of the firstlayer of products on the pallet (or on the stack of layers of productsalready palletized).

The loading device advantageously comprises at least two parallel sides,which are associated to activating means which move at least one of thesides horizontally nearingly and distancingly to and from the otheredge, such as to clamp and release the first layer of products which isrested on the support means in a closed configuration.

In this way the first layer of products can be perfectly centred withrespect to the support means and with all the products perfectlycompacted, in such a way as to be released perfectly centred andbalanced on the pallet.

A still further aspect of the invention comprises a palletizing plantwhich includes at least a palletizing device, as described above, aconveyor and grouping line of products to be palletized located upstreamof the palletizing device with respect to the advancement direction ofthe products along the conveyor and grouping line and at least afollower platform interposed between the conveyor and grouping line andthe palletizing device is vertically mobile independently of thepalletizing device in such a way as to position itself, alternatively,at the level of the conveyor and grouping line for unloading a layer ofproducts therefrom and at the level of the palletizing device forloading the layer of products onto the storage platform of thepalletizing device.

A further aspect of the invention discloses a loading device which isalso independently protectable from the one detailed above, whichcomprises a lower plane able to supportingly receive a pallet and aloading device positioned above the lower plane (vertically mobile orfixed) and comprising an upper platform, superposed in plan view on thelower plane and provided with support means having a variableconfiguration and activating means able to cyclically move the supportmeans between a closed configuration, in which they define a support fora first layer of products to be palletized, and an open configuration,in which they remove the support in order to release the first layer ofproducts downwards, in which the loading device comprises a positioningorgan able to position or release a support sheet element onto the firstlayer of products.

Further, the further palletizing device can comprise a storage plane andconveyor means as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will emerge froma reading of the following description provided by way of non-limitingexample, with the aid of the figures illustrated in the accompanyingtables.

FIG. 1 is a view from above of a palletizing plant according to theinvention.

FIG. 2 is a view along section line II-II of FIG. 1, with thepalletizing device in a first operating configuration.

FIG. 3 is a view of FIG. 2, with the palletizing device in a secondoperating configuration.

FIG. 4 is a view of FIG. 2 with the palletizing device in a thirdoperating configuration.

FIG. 5 is a view of FIG. 2 with the palletizing device in a fourthoperating configuration.

FIG. 6 is a view along the section line VI-VI of FIG. 1.

FIG. 7 is a detail of the loading device of the invention, in a firstoperating configuration.

FIG. 8 is the loading device of FIG. 7, in a second operatingconfiguration.

FIG. 9 is the loading device of FIG. 7 in a third operatingconfiguration.

FIG. 10 is the loading device of FIG. 7 in a fourth operatingconfiguration.

FIG. 11 is a view along section line XI-XI of FIG. 10.

BEST WAY OF CARRYING OUT THE INVENTION

With particular reference to the figures, 10 denotes in its entirety adevice, in palletizing plants 1, for palletizing loads 4 of bottles,cans, jars or the like, without excluding the possible of its being usedfor palletizing other packed products.

The palletizing device 10 (FIGS. 2-5) comprises a lower plane 15.

The lower plane 15 comprises a motorized roller plane 16 able to definea horizontal loading plane for a pallet 5 for loading layers of loads 4and overall defines a conveyor line for the loaded pallets 5 of thestack of loads 4.

In particular, the motorized roller plane 16 is served by a loadingroller plane able to advance empty pallets 5 towards the motorizedroller 16 as is known to the technical expert in the sector.

Naturally the motorized roller plane 16 can be replaced by other typesof motorized conveyors of known type.

The palletizing device 10 comprises a loading device 100 which issuperposed in plan view on at least a tract of the lower plane 15 and isvertically mobile alternatively between at least a lowered configurationin which it is close to the lower plane 15 and at least a raisedconfiguration in which it is distanced therefrom.

The palletizing device 10 comprises a portal structure 17 comprising twovertical columns 18 respectively located on opposite sides of themotorized roller plane 16.

Each vertical column 18 defines a vertical guide for the loading device100.

The loading device 100 (with particular reference to FIGS. 7-10)comprises an upper platform 110 able to contain a first compacted layerof loads 4 such as to occupy an area that is substantially equal to thesupport area defined by a pallet 5.

In practice, the loading device 100 comprises a pair of lateral flanks111 that are vertical and opposite (of which one only is visible in thefigures), between which a shutter 112 is interposed.

The shutter 112 can take on a closed configuration (FIG. 7) in which ahorizontal loading plane is made available and is able to restinglysupport the loads 4, and an open configuration (FIG. 8) in which itleaves a passage open in such a way as to enable the descent of thefirst layer of loads 4 by force of gravity.

In practice, the shutter 112 in the open configuration is able to definean area that is substantially equal to the support area defined by thepallet 5.

In more detail, the shutter 112 comprises two groups of support rollers,denoted respectively by 113 and 114, which are horizontal and theopposite ends of which are associated to meshes of two identical guideand support chains 115, which are opposite and respectively associatedto the two lateral flanks 111.

Each guide and support chain 115 lies in a vertical plane and is atleast partially wound about an assembly of respective cogged pinions.

All the cogged pinions can be connected to one another, and in any caseare such that the two guide and support chains 115 always slide insynchrony and at the same velocity.

The support rollers 113 and 114 are fixed, parallel to one another(perpendicular to the lateral flanks 111) and neared to one another.

In this way, the two groups of support rollers 113 and 114, when nearedto one another, take on a closed configuration, in which they arecoplanar and neared, and wherein they thus define a single load planeable to support the loads 4.

Starting from this closed configuration, the guide and support chains115 can be activated to slide, in such a way that the groups of supportrollers 113 and 114 reciprocally distance by moving in oppositedirections, up to reaching an open configuration in which they leave apassage open below the loads 4.

The guide and support chains 115 can go from the open configuration tobeing activated to slide in the opposite direction, such as to returnthe groups of support rollers 113 and 114 into the initial closedconfiguration.

The activating of the guide and support chains 115 (FIG. 7) is carriedout by one or more motors (of known type), each able to rotate at leastone of the cogged pinions on which the chains are wound.

For each first layer of loads 4 to be positioned at the centre of theload plane, the loading device 100 comprises a thrust organ 116 servingthe upper platform 110, which is provided with a to and fro up and downmotion in a horizontal and parallel direction to the load plane definedby the groups of support rollers 113 and 144 in a closed position, andto rise and fall.

The thrust organ 116, i.e. a transversal bar located with a longitudinalaxis parallel to the rollers of the support roller groups 113 and 114,is supported at the lateral flanks 21 of the loading device 100 andguided to move in an up and down and to and fro motion.

During the forward travel, the thrust organ 116 is lowered such as topush an entire first layer of loads 4 to slide on the support rollers113 and 114 (idle rollers) up to halting against an endrun element 117,also realized by a bar positioned with a longitudinal axis parallel tothe rollers of the groups of support rollers 113 and 114, which isparticularly fixed to the lateral flanks 21.

During the return travel, the thrust organ 116 is raised such as to passabove the first layer of loads 4.

The thrust organ 116 is activated by motor means of known type and notillustrated.

The loading device 100 comprises a storage platform 120 defining asupport for a second layer of loads 4 to be palletized, for example alsocompacted such as to occupy an area that is substantially equal to thesupport area defined by a pallet 5, which is flanked (i.e. aligned andlocated upstream along the advancement direction imparted by the loadingdevice 100, in particular by the thrust organ 116, on the first layer ofloads 4) to the upper platform 110.

Thanks to the storage platform 120 and the upper platform 110, theloading device 100 is able to support two layers of loads 4 at a time,flanked/aligned horizontally.

In practice, the storage platform 120 is supported by the lateral flanks111 which support the upper platform 110 and precedes it in theadvancement direction of the loads 4 towards the upper platform.

The storage platform 120 in the illustrated example comprises a conveyorbelt 121 which is coplanar and neared to the load plane defined by theclosed shutter 112.

Further, when the shutter 112 is in the open configuration, the group ofsupport rollers 113 can be arranged substantially below the storageplatform 120.

The conveyor belt 121 can transport the second layer of loads 4 towardsthe upper platform 110, which second layer is in arrival for examplefrom a conveyor and grouping line 2 of a palletizing plant 1 (as will bemore fully explained in the following), causing it to rise onto the loadplane defined by the shutter 112.

In practice the conveyor belt 121 comprises one or more flexible belts122 (or chains) each of which is loop-wound on itself and is wound on atleast a drive pulley 123, keyed on the output shaft of a motor 124supported by the lateral flanks 21, and one or more driven pulleys 125singly keyed on respective idle shafts parallel and rotatably associatedto the lateral flanks.

In practice, the idle rollers are arranged parallel to the rollers ofthe groups of support rollers 113 and 114 of the upper platform 110.

The active upper branch of the belts 122 of the storage platform 120 issubstantially coplanar to the plane of the upper platform (of the groupsof support rollers 113 and 114) when it is in the closed configuration.

It is further possible for the storage platform 120 to comprise,alternatively, a different type of conveyor, for example a motorizedroller or the like.

The loading device 100 further comprises a positioning organ 130 whichis able to position and release (as will more fully emerge in thefollowing) a sheet element, for example a cardboard sheet 6, on thefirst layer of loads 4 centred and resting on the shutter 112.

The loading device 100 in particular comprises a storage plane 140 of atleast a stack of cardboard sheets 6 which loading device 100 serves thepositioning organ 130.

The storage plane 140 is preferably vertically mobile in synchrony withthe loading device 100 by means of suitable motors, along verticalguides associated to a fixed upright 141 (see FIG. 6) supported by theportal structure 17 comprising the two vertical columns 18 which enablevertical translation of the loading device.

The storage plane 140 advantageously comprises a further conveyor belt142 suitably motorized and defining a horizontal advancement plane ofthe stack of cardboard sheets 6 able to move it along a perpendiculardirection to the advancement direction of the layer of loads 4 on theconveyor belt 121.

In practice the further conveyor belt 142 is superposed in plan on andsuspended at a distance from the conveyor belt 121, remainingsubstantially equidistant therefrom even during the vertical motion ofthe loading device 100.

The further conveyor belt 142 can receive the stack of cardboard sheets6 from a usual conveyor device of stacked sheets, by interposing acounter and stacker device that defines a stack of a predeterminednumber of cardboard sheets 6 centred on the further conveyor belt 142,not illustrated in detail herein.

The loading device 100 further comprises conveyor means 150 of acardboard sheet 6 at a time, which comprise a gripping system that cancollect a cardboard sheet 6 at a time from the stack of cardboard sheets6 arranged on the further conveyor belt 121, for example by collectingfrom above the sheet located superiorly on the stack, and a translationsystem of the cardboard sheet 6 collected, which are able to bring thecardboard sheet 6 into an unloading position, in which the cardboardsheet 6 is substantially superposed in plan on the first layer of loads4 which is positioned resting on the shutter 112.

The gripping system comprises at least a plurality of first suckers 151which can be arranged in a loading position, in which they aresuperposed in plan view on the stack of cardboard sheets 6 stacked onthe further conveyor belt 142, for collection from above of theuppermost cardboard sheet 6 by effect of the suckers.

In practice, the translation system, which is able to translate thefirst suckers 151 alternatively between the loading position and theabove-cited unloading position, comprises a conveyor belt (FIG. 11)fixed to the lateral flanks 111 of the loading device 100.

In practice, the conveyor belt 152 is superposed in plan view on thestorage platform 120 and the upper platform 110, such that the firstsuckers 151 in the loading position are superposed on the storageplatform 120 and in the unloading position on the upper platform 110.

The conveyor belt 152 comprises one or more flexible belts 153 (in theillustrated example two), loop-closed and each wound about a driveroller 154 (connected to a respective motor) and a driven roller 155rotatably associated to the lateral flanks 111.

One or more groups of first suckers 151 are associated to each belt 153,aligned along the longitudinal direction of the belt 153 (in the exampletwo distinct groups of five first suckers 151 are shown for each belt153).

The belt conveyor 152 comprises a tubular frame comprising, for eachbelt 153, at least a longitudinal member 156 having a substantiallyC-shaped transversal section, each respectively parallel to the lowertract of the belt 153, and located above it.

Each belt 153 when sliding internally of the longitudinal member 156 isin practice able to close (substantially sealingly) a longitudinalchamber 157 (as visible in FIG. 11) defined between the internal wallsof the longitudinal members 156 and the internal wall of the belt 153,which is placed in slight depression by a suitable aspirating group (notillustrated) set in communication with the longitudinal chamber by meansof suitable branchings, not illustrated.

Each first sucker 151 is associated to the belt 153 in such a way as toproject externally of the external wall of the belt.

In practice, each first sucker 151 comprises a deformable cup 158 inwhich a conduit 159 opens, which is able to be inserted snuglyinternally of a through-hole made in the belt 153 and fixed thereto.

The conduit 159 is therefore able to set in fluid communication thelongitudinal chamber 157 with the internal volume of the deformable cup158 such as to generate a slight depression about it and to thus be ableto attract and retain, by suction effect, a cardboard sheet 6 arrangedbelow the first suckers 151.

In practice, each group of first suckers 151, when facing downwards atthe lower tract of the bet 153, can collect a cardboard sheet 6 from thestack of sheets rested on the storage plane 140 and bring it to theunloading position, in which it superposes in plan view and at adistance from the shutter 112.

The positioning organ 130 comprises at least a horizontal arm 131 (inthe example two in number and parallel and coplanar) which is associatedslidably with the lateral flanks 21 of the loading device 100 by meansof vertical guides 133; this arm 131 can be arranged in the interspacepresent between the belts 153 of the conveyor belt 152 with thelongitudinal axis substantially parallel to the longitudinal axis of thebelts.

Each arm 131 is vertically mobile between a raised position, in which itis at a higher level than the level of the first suckers 151 when theyare in the unloading position, and a lowered position, in which the arm131 is resting on the first layer of loads 4 with a cardboard sheet 6interposed.

Each arm 131 is inferiorly provided with at least a second sucker 132(two in the illustrated example) facing downwards; in the raisedposition the second sucker 132 is at a higher level than the firstsuckers 151, while in the lowered position it is at a lower level thanthem.

In practice, in passing from the raised position to the lowered positionthe arm 131 and therefore each second sucker 132 comes into contact fromabove with the cardboard sheet 6 which is maintained in the unloadingposition from the first suckers 151 and, when collecting the cardboardsheet, draws it to rest on the first layer of loads 4 located on theshutter 112 in the closed configuration.

The end of each arm 131 constrained to slide along the vertical guides133 fixed to the lateral flanks 21 is activated upwards by a linearactuator (not illustrated), while it is free to slide downwards byeffect of the weight force acting on the arm 131, thus in any casemaintaining the arm substantially horizontal, up to resting on the firstlayer of loads 4. The arm, alternatively, might be commanded intranslation in the two directions by a suitable actuator.

The vertical guides 133 exhibit a lower extra-run so as to enable afurther vertical translation of the arm 131 downwards, such that it canaccompany the “free” fall of the first layer of loads 4 when the shutter112 is opened, while staying supported on the first layer of loads 4 byinterposing of the cardboard sheet 6.

The palletizing plant 1 (see FIG. 1) further comprises a conveyor andgrouping line 2 of loads 4 to be palletized, which comprises, forexample, a linear conveyor and handlers able to position the loads 4such as to group them in single layers of loads separated from oneanother and able to optimize the position thereof as a function of thesupport area made available by a pallet 5.

In the illustrated example (FIG. 2) the conveyor and grouping line 2 ispositioned at a higher level (though not by much) with respect to thelower plane 15.

In practice, the conveyor and grouping line 2 is located upstream of thepalletizing device 10 with respect to the advancement direction of theloads 4 along the conveyor and grouping line.

Further, the palletizing plant 1 comprises a follower platform 3, whichis interposed between the conveyor and grouping line 2 and thepalletizing device 10.

The follower platform 3 (FIG. 2) is vertically mobile independently ofthe palletizing device 10 and can be arranged, alternatively,substantially coplanarly and aligned (substantially continuously) to theconveyor and grouping line 2, such as to enable unloading of a layer ofloads 4 from the linear conveyor of the conveyor and grouping line, andsubstantially coplanar and aligned (substantially continuously) to thepalletizing device 10 (in the instantaneous position thereof) such as toenable loading the layer of loads 4, temporarily resting on the followerplatform 3, onto the storage platform 120 of the palletizing device 10.

In practice the follower platform 3 comprises a mobile plane 31, forexample a conveyor belt or the like, which is associated to a frame 32slidably associated to a pair of fixed vertical guide bars 33, forexample, to the portal structure 17 to which the vertical columns 18supporting the loading device 100 are fixed.

The follower platform 3 is activated in vertical translation byindependent motors, for example provided with encoders, which follow thepositioning/vertical translation of the loading device 100.

The functioning of the palletizing plant 1 is the following.

At the start, the empty pallet 5 stations on the motorized roller plane16 in the loading position.

The empty follower platform 3 is at the height of the conveyor andgrouping line 2. The empty loading device 10 finds the shutter 112 ofthe upper platform 110 in the closed configuration at the height of thefollower platform 3.

At this point three successive layers of loads 4 advance from the line 2and position respectively on the upper platform 110, the storageplatform 120 and the follower platform 3.

The following events then contemporaneously occur.

The loading device 100 lowers down to placing the shutter 112 just abovethe pallet 5; the shutter 112 opens to deposit the layer of loads on thepallet 5, the loading device 100 and the follower platform 3 are raisedby a quantity equal to the height of the layer of loads 4, the shutter112 closes again while the follower platform 3 sends the layer of loads4 onto the storage platform 120.

The follower platform 3 continues to rise such as to bring itself to theheight of the line 2, where it receives a new layer of loads 4 and thestorage platform 120 sends the layer of loads 4 onto the upper platform110.

While the upper platform 110 (shutter 112) is re-opening, re-closes andrises, the follower platform 3 arrives with a new layer of loads 4 andsends it onto the storage platform 120.

The cycle is repeated.

At substantially the same time as the transfer of the first layer ofloads 4 from the storage platform 120 to the upper platform 110 thegripping means (the first suckers 151) collect a cardboard sheet 6 fromthe pile of sheets lying on the storage plane 140 (see FIG. 8) and theconveyor means 150 take it from the loading position to the unloadingposition (see FIGS. 7, 9, 10 in a broken line), such that as soon as thefirst layer of loads 4 is resting on the closed shutter 112 thepositioning organ 130 positions the cardboard sheet 6 on the first layerof loads 4 (see FIGS. 7, 9, 10 in the unbroken line), reducing to aminimum the waiting times of the positioning of the cardboard sheet 6 onthe layer of loads 4 available for arranging on the pallet 5.

From the above it is clear that once the plant is working at operatingspeed the operations of stacking a layer of loads 4 on the pallets 5 anddepositing a further sheet of cardboard 6 are carried out substantiallycontemporaneously with respect to the unloading operations of a layer ofloads 4 from the conveyor and grouping line 2, thus saving time andobtaining a greater productivity of the palletizing plant 1.

Obviously the palletizing plant 1 described above can be subject tonumerous modifications of a technical-applicational nature withoutforsaking the scope of the invention as claimed in the following.

1. A palletizing device (10) comprising a lower plane (15) able tosupportingly receive a pallet (5) and a loading device (100) verticallymobile above the lower plane (15) and comprising an upper platform(110), superposed in plan view on the lower plane (15) and provided witha variable-configuration support mechanism (112) and an actuatorconfigured to cyclically move the support mechanism (112) between aclosed configuration, in which they define a support for a first layerof products (4) to be palletized, and an open configuration, in whichthey remove the support in order to release the first layer of products(4) downwards, wherein the loading device (100) comprises a storageplatform (120), defining a support for a second layer of products (4) tobe palletized, flanked to and rigidly connected to the upper platform(110).
 2. The palletizing device (10) of claim 1, wherein the loadingdevice (100) comprises a positioning member (130) configured to positionand release a sheet support element (6) onto the first layer of products(4).
 3. The palletizing device (10) of claim 2, wherein the loadingdevice (100) comprises a storage plane (140) of at least a stack ofsheet elements (6) serving the positioning member (130).
 4. Thepalletizing device (10) of claim 2, wherein the loading device (100)comprises a conveyor mechanism (150) of a sheet element (6) at a timewhich conveyor mechanism (150) is provided with a gripping system (151)of a sheet element (6) of the stack of sheet elements (6) and atranslation system (152) of the gripped sheet element (6), able to bringthe gripped sheet element (6) into an unloading position, in which thesheet element (6) is substantially superposed in plan view on the firstlayer of products (4).
 5. The palletizing device (10) of claim 4,wherein the gripping system comprises at least a first sucker (151) ableto be arranged in a loading position, in which the first sucker (151) issuperposed superiorly to the stack of sheet elements (6), for grippingthe uppermost sheet element (6) from above, the translation system (152)being able to translate the first sucker (151) alternatively between theloading position and the unloading position.
 6. The palletizing device(10) of claim 5, wherein the first sucker (151) comprises a deformablecup (158) into which a conduit (159) opens, said conduit (159) isassociated to an aspirating group able to define a slight depression atthe internal zone of the deformable cup (158).
 7. The palletizing device(10) of claim 5, wherein the positioning member (130) comprises at leastan arm (131) that is vertically mobile between a raised position, inwhich it is at a higher level than the first sucker (151) in theunloading position, and a lowered position, in which it is resting onthe first layer of products (4) with the sheet element (6) interposed.8. The palletizing device (10) of claim 1, wherein the loading device(100) comprises at least two parallel sides (116, 117), which areassociated to an actuator which can move at least one of the sides (116)horizontally nearingly and distancingly to and from the other side(117), such as to clamp and release the first layer of products (4)which is rested on the support mechanism (112) in a closedconfiguration.
 9. A palletizing plant (1) which comprises at least apalletizing device (10), according to claim 1, a conveyor and groupingline (2) of products (4) to be palletized located upstream of thepalletizing device (10) with respect to the advancing direction of theproducts (4) along the conveyor and grouping line and at least afollower platform (3) interposed between the conveyor and grouping line(2) and the palletizing device (10) is vertically mobile independentlyof the palletizing device (10) in such a way as to position itself,alternatively, at the level of the conveyor and grouping line (2) forunloading a layer of products (4) therefrom and at the level of thepalletizing device (10) for loading the layer of products (4) on thestorage platform (120) of the palletizing device (10).